unknown syntax error in python
Line 25 is missing a closing bracket. Python assumes line 27 is part of the high = (h) parameter to the sound_bake() function.

    bpy.ops.graph.sound_bake(filepath=r'path/to/file' , low = (l), high = (h)


should be:

    bpy.ops.graph.sound_bake(filepath=r'path/to/file' , low = (l), high = (h))